IAS-Research Talk (Online) by Derek Skillings (University of North Carolina at Greensboro): «Can host-microbiome systems be healthy? Shaping ecosystems vs curing disease»

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02/06/2020, at 16:00

To participate, please contact: guglielmo.militello@ehu.eus

ABSTRACT: Host-associated microbiomes play a variety of important roles in host health and disease. Attempts to understand and make predictions about complex host-microbiome interactions have led many researchers to talk about microbiomes—especially human-associated ones—in terms of being either healthy or dysbiotic. In this presentation I will look at some alternatives for making sense of “healthy microbiome” talk. I will argue that existing “naturalistic”, or non-evaluative, accounts of human health are not appropriate for microbiomes, and that notions of ecosystem health face similar shortcomings. These problems suggest that “microbiome health” might only be definable in evaluative terms and may never extend beyond a metaphor to organismal health. I will end by looking at some possibilities for understanding overall host health given the importance and ubiquity of microbiomes.

IAS-Research Talk (Online) by Giorgio Airoldi (UNED): «Beyond Fitness: Robustness as measure of non-selective evolutionary phenomena «

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Date: 16/06/2020, at 11:30

To participate, please contact: guglielmo.militello@ehu.eus

ABSTRACT:

The last decades have seen the flourishing of accounts of evolutionary forces other than selection, many of which have been collected under the name of Extended Evolutionary Synthesis (ESS) (Laland et al. 2015). The range of phenomena targeted by these accounts spans from genetic mechanisms (e.g. Cherniak & Rodriguez-Esteban 2013, Kimura 1983, Wagner 2015) to developmental (e.g. Maynard Smith  et al. 1985), systemic (e.g. Kauffman 2000) and neo-Lamarckian (e.g. Koonin & Wolf 2009).

Although almost none of them denies the importance and even preponderance of selection in the history of life, and they rather aim at integrating non-selective phenomena into neo-Darwinism (a view known as ‘pluralism’), they are highly criticized by main-stream biology, that either limits or completely denies their evolutionary importance, often underling that their contribution to fitness is immaterial.

In this talk, I claim that fitness, being an intrinsically selective measure, should not be used to judge non-selective phenomena. I show how, by doing so, the theory of selection falls into the well-known pitfall of becoming a truism. To avoid the pitfall, I propose to recur to robustness as a selective-indifferent variable able to account for the contribution to evolution of non-selective forces. After defining robustness, I analyse some of the mechanisms that increase the robustness of a system and I suggest how non-selective phenomena can contribute to the appearance of such mechanisms in organisms. Finally, I propose a classification of evolutionary phenomena in terms of changes of form and function, and I show how fitness and robustness might jointly explain them in a unified, pluralistic account of evolution.

References

Cherniak, C.; Rodriguez-Esteban, R. (2013). Body maps on the human genome. Mol. Cytogenet. 6 (1): 61Kauffman, S., (2000). Investigations. Oxford University Press.

Kimura, M. (1983). The neutral theory of molecular evolution. Cambridge University Press

Koonin, E. V., Wolf, Y. I (2009). Is evolution Darwinian or/and Lamarckian? Biology Direct, 4:42

Laland K.N., Uller T., Feldman M.W., Sterelny K., Müller G.B., Moczek A., Jablonka E., Odling-Smee J. (2015). The extended evolutionary synthesis: its structure, assumptions and predictions. Proc. R. Soc. B 282: 20151019

Maynard Smith, J., Burian, R., Kauffman, S., Alberch, P., Campbell, J., Goodwin, B., Lande, R., Raup, D., Wolpert, L. (1985). Developmental Constraints and Evolution: A Perspective from the Mountain Lake Conference on Development and Evolution. The Quarterly Review of Biology, (60)  3: 265-287

Wagner, A., (2011), The Origins of Evolutionary Innovations, Oxford University Press

IAS-Research Talk (Online) by Juan M. Loaiza: «Sandboxing: A Specification Hierarchy of Contexts of Constraint Interdependence»

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Date: 09/06/2020, at 11:30

To participate, please contact: guglielmo.militello@ehu.eus

ABSTRACT:

In this presentation I propose to bring interest to seemingly peripheral aspects of the theory of organisational closure based on constraint dependencies (Moreno & Mossio, 2015; Montévil & Mossio, 2015). In particular, I show how the theory can generate an alternative mapping of levels or hierarchies of organisation.The question I address is how contexts come about. I use Salthe’s distinction of compositional and specification hierarchies and show how the latter combined with some of the consequences of the constraint-based theory yields an interesting alternative. Compositional (or scalar) hierarchies are almost the default assumption across various disciplines (e.g. by adding parts we can go progressively from subatomic particles to populations, etc.). The alternative consists of an open-ended specification hierarchy of contexts which I call tentatively the “sandboxes” hierarchy (in reference to the metaphor of sandboxing in software development). By focusing on mapping contexts (the periphery), as a complement to the established theory of organisational closure (the centre), I point to possible integrative links across nomothetic and idiographic perspectives.   

IAS-Research Seminar (Online) by Leonardo Bich (EHU/UPV), «Multicellularity: realizing functional integration by organising the intercellular space»

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Tuesday, 26/05/2020 at 11:30 (online, please contact guglielmo.militello@ehu.eus)

Abstract

Paper available (open access) here:
https://www.frontiersin.org/articles/10.3389/fphys.2019.01170/full

The question addressed in this talk is how multicellular systems realise functionally integrated physiological entities by organising their intercellular space. 

From a perspective centred on physiology and integration, biological systems are often characterised as organised in such a way that they realise metabolic self-production and self-maintenance. The existence and activity of their components rely on the network they realise and on the continuous management of the exchange of matter and energy with their environment. One of the virtues of the organismic approach focused on organisation is that it can provide an understanding of how biological systems are functionally integrated into coherent wholes.

Organismic frameworks have been primarily developed by focusing on unicellular life. Multicellularity, however, presents additional challenges to our understanding of biological systems, related to how cells are capable to live together in higher-order entities, in such a way that some of their features and behaviours are constrained and controlled by the system they realise. Whereas most accounts of multicellularity focus on cell differentiation and increase in size as the main elements to understand biological systems at this level of organisation, these factors are insufficient to provide an understanding of how cells are physically and functionally integrated in a coherent system.

To address these issues, I present a new theoretical framework of multicellularity. The thesis is that one of the fundamental theoretical principles to understand multicellularity, which is missing or underdeveloped in current accounts, is the functional organisation of the intercellular space. From this perspective, the capability to be organised in space plays a central role in this context, as it enables (and allows to exploit all the implications of) cell differentiation and increase in size, and even specialised functions such as immunity. The extracellular matrix plays a crucial active role in this respect, together with the strategies employed by multicellular systems to exert control upon internal movement and communication. Finally, I show how the organisation of space is involved in some of the failures of multicellular organisation, such as aging and cancer.

IAS Research Seminar, Kepa Ruiz-Mirazo’s talk, «The construction of biological ‘inter-identity’ as the outcome of a complex process of protocell development in prebiotic evolution»

To participate online, please contact: guglielmo.militello@ehu.eus.

Date: 12/05/2020, at 11:30

Abstract: The concept of identity is used both (i) to distinguish a system as a particular material entity that is conserved as such in a given environment (token-identity: i.e., identity as permanence or endurance over time), and (ii) to relate a system with other members of a set (type-identity: i.e., identity as an equivalence relationship). Biological systems are characterized, in a minimal and universal sense, by a highly complex and dynamic, far-from-equilibrium organization of very diverse molecular components and transformation processes (i.e., ‘genetically-instructed cellular metabolisms’) that maintain themselves in constant interaction with their corresponding environments, including other systems of similar nature. More precisely, all living entities depend on a deeply convoluted organization of molecules and processes (a naturalized von Neumann constructor architecture) that subsumes, in the form of current individuals (autonomous cells), a history of ecological and evolutionary interactions (across cell populations). So one can defend, on those grounds, that living beings have an identity of their own from both approximations: (i) and (ii). These transversal and trans-generational dimensions of biological phenomena, which unfold together with the actual process of biogenesis, must be carefully considered in order to understand the intricacies and metabolic robustness of the first living cells, their underlying uniformity (i.e., their common biochemical core) and the eradication of previous –or alternative– forms of complex natural phenomena. Therefore, a comprehensive approach to the origins of life requires conjugating the actual properties of the developing complex individuals (fusing and dividing protocells, at various stages) with other, population-level features, linked to their collective-evolutionary behaviour, under much wider and longer-term parameters. On these lines, I will argue that life, in its most basic sense, here on Earth or anywhere else, demands crossing a high complexity threshold and that the concept of ‘inter-identity’ can help us realize the different aspects involved in the process.